In-situ segregation of A-site defect (La0.6Sr0.4)0.90Co0.2Fe0.8O3-δ to form a high-performance solid oxide fuel cell cathode material with heterostructure

Segregation and interdiffusion processes in perovskites: a review of recent advances

“…The main problems that may arise are related to insufficient oxygen reduction reaction activity, segregation processes and CO 2 poisoning. For lanthanum-strontium cobalt-ferrite, mixed segregation mechanisms are prevalent, which include segregation of Sr at the electrode surface, [155][156][157] formation of heterostructures such as (La 0.6 Sr 0.4 ) 0.90 Co 0.2 Fe 0.8 O 3−d /Co 2 FeO 4 /CoFe 2 O 4 due to segregation of B-site elements 158 or isolated large Co 3 O 4 particles on the LSCF surface predominantly between the grains of the main phase. 159 It is known that the processes of strontium segregation are not uniform with depth.…”

Improving Electrochemical Oxidation/Reduction Kinetics in Single-Component Solid Oxide Cells through Synergistic A-Site Defects and Anion Doping

“…Among these materials, the perovskite La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) oxide has gained wide recognition and usage due to its acceptable hydrogen oxidation/oxygen reduction activity and good tolerance against moisture atmosphere. 13,14 Recently, various strategies have been explored to enhance the catalytic activity of electrode materials for both conventional and single-component SOCs. 15−17 For example, introducing A-site defects in (La 0.6 Sr 0.3 )CrO 3-δ hydrogen electrode material has been shown to significantly enhance the concentration of oxygen vacancies, thus improving catalytic activity.…”

“…19 Generally, the introduction of an appropriate level of A-site deficiency in perovskite oxides can optimize the crystal structure and improve the electrical conductivity. 14 Furthermore, the partial substitution of O in perovskite oxides with fluorine effectively weakens metal−oxygen bonds, activates lattice oxygen, and introduces additional oxygen vacancies. 20 Therefore, it can be inferred that the simultaneous application of A-site deficiency and fluorine doping strategies to perovskite oxides may result in an increase in both the conductivity and oxygen vacancy concentration.…”

“…Semiconductor materials play a vital role in the reactions taking place at both electrodes and therefore have specific structural and activity requirements. , In general, electrode materials must have excellent catalytic oxidation and reduction activity, as well as good stability under high temperature and high humidity conditions. Among these materials, the perovskite La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3‑δ (LSCF) oxide has gained wide recognition and usage due to its acceptable hydrogen oxidation/oxygen reduction activity and good tolerance against moisture atmosphere. , Recently, various strategies have been explored to enhance the catalytic activity of electrode materials for both conventional and single-component SOCs. − For example, introducing A-site defects in (La 0.6 Sr 0.3 )­CrO 3‑δ hydrogen electrode material has been shown to significantly enhance the concentration of oxygen vacancies, thus improving catalytic activity . Similarly, the substitution of O 2– with alternative anions such as F – and Cl – has also been identified as an effective approach.…”

“…In the study by Dai et al, the catalytic activity of La 1– x Sr x FeO 3−δ X σ (X = F, Cl) was investigated, alongside La 1– x Sr x FeO 3−δ ( x = 0–0.8), for the oxidative dehydrogenation of ethane . Generally, the introduction of an appropriate level of A-site deficiency in perovskite oxides can optimize the crystal structure and improve the electrical conductivity . Furthermore, the partial substitution of O in perovskite oxides with fluorine effectively weakens metal–oxygen bonds, activates lattice oxygen, and introduces additional oxygen vacancies .…”